As an alternative factor to produce asymmetry between left and right vocal folds, the present study focuses on level difference, which is defined as the distance between the upper surfaces of the bilateral vocal folds in the inferior-superior direction. Physical models of the vocal folds were utilized to study the effect of the level difference on the phonation threshold pressure. A vocal tract model was also attached to the vocal fold model. For two types of different models, experiments revealed that the phonation threshold pressure tended to increase as the level difference was extended. Based upon a small amplitude approximation of the vocal fold oscillations, a theoretical formula was derived for the phonation threshold pressure. This theory agrees with the experiments, especially when the phase difference between the left and right vocal folds is not extensive. Furthermore, an asymmetric two-mass model was simulated with a level difference to validate the experiments as well as the theory. The primary conclusion is that the level difference has a potential effect on voice production especially for patients with an extended level of vertical difference in the vocal folds, which might be taken into account for the diagnosis of voice disorders.
ABSTRACT;Because of many reasons such as increasing population, industrial development, and expanding irrigation, which are expected to continue in future, shortage of water resources has become more severe in many parts of the world. In order to assess the balance between water demand and supply in future under climate change, surface runoff and water demand in each river basin are estimated from 2050 through 2059. It is found that the estimated spatial patterns of runoff change in 2050s differ considerably by GCM used, especially in Central Africa and the north part of South America .In developed countries, industrial water demand will increase, while agricultural water demand will slightly decrease. In developing countries, water demand will increase in all sectors, especially the share of industrial water demand will increase significantly.
IntroductionIt has been known that asymmetry between left and right vocal folds, induced, e.g., by vocal cord nodules, polyps, and vocal cord atrophy, is one of the leading causes of voice disorders. The asymmetric configuration may lead to incomplete glottal closure and results in a variety of voice instabilities such as subharmonics, biphonation, and chaos. Careful examinations are needed to investigate the effect of asymmetry on the voice production. The preceding studies mainly focused on asymmetry with respect to tension imbalance and geometrical difference between the left and right vocal folds. It has been known, however, that the level difference, that is defined as the distance between the upper surfaces of the bilateral vocal folds in the inferior-superior direction, is also a typical result of atrophy of the paralyzed vocal fold. Kadota and Yumoto [9] measured the level difference of patients with unilateral recurrent laryngeal nerve paralysis using a computed radiography system and reported that the level difference provides a good index for the quantitative assessment of the effectiveness of phonosurgical treatment. Hong and Jung [10] also reported a variety of level differences between paralyzed and normal vocal folds for patients with unilateral vocal fold paralysis.Although the level difference between the left and right vocal folds may have an influence on laryngeal functions, its effect on voice production has not yet been thoroughly investigated. The aim of the present letter is to utilize three types of physical models of the vocal folds to study the effect of the level difference on the vocal folds vibration. We measure the phonation threshold pressure as a primary index for quantifying the difficulty in phonation. Our experiments reveal that the phonation threshold pressure increases signifi-
We present a novel concept audio–visual object removal in 360-degree videos, in which a target object in a 360-degree video is removed in both the visual and auditory domains synchronously. Previous methods have solely focused on the visual aspect of object removal using video inpainting techniques, resulting in videos with unreasonable remaining sounds corresponding to the removed objects. We propose a solution which incorporates direction acquired during the video inpainting process into the audio removal process. More specifically, our method identifies the sound corresponding to the visually tracked target object and then synthesizes a three-dimensional sound field by subtracting the identified sound from the input 360-degree video. We conducted a user study showing that our multi-modal object removal supporting both visual and auditory domains could significantly improve the virtual reality experience, and our method could generate sufficiently synchronous, natural and satisfactory 360-degree videos.
The vocal folds, which are constituted by muscles covered with a mucous membrane, generate a primary sound called the voice source, as airflow passes them. In some voice disorders, asymmetry between left and right vocal folds was observed. We focus on level difference, which is defined as the distance between the upper surfaces of the bilateral vocal folds in the inferior-superior direction and is caused by symptom of such disorders. Physical models of the vocal folds were utilized to study the effect of the level difference on the phonation threshold pressure. For three types of different self-oscillating synthetic models, our experiments reveal that the phonation threshold pressure increases significantly as the level difference is extended. Furthermore, based upon a small amplitude approximation of the vocal fold oscillations, a theoretical formula was derived for the phonation threshold pressure. Our theory was in good agreement with the experiments, especially when the phase difference between the left and right vocal folds is not too large. From these results, we conclude that the level difference affects voice production, therefor the effect of the vocal fold geometry needs to be taken into account for the observation of voice disorders.
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